conf: add dynamic interface

Knot.files

@@ -197,6 +197,8 @@ src/knot/conf/conf.c
 src/knot/conf/conf.h
 src/knot/conf/confdb.c
 src/knot/conf/confdb.h
+src/knot/conf/confio.c
+src/knot/conf/confio.h
 src/knot/conf/scheme.c
 src/knot/conf/scheme.h
 src/knot/conf/tools.c

src/Makefile.am

@@ -213,6 +213,8 @@ libknotd_la_SOURCES =				\
 	knot/conf/conf.h			\
 	knot/conf/confdb.c			\
 	knot/conf/confdb.h			\
+	knot/conf/confio.c			\
+	knot/conf/confio.h			\
 	knot/conf/scheme.c			\
 	knot/conf/scheme.h			\
 	knot/conf/tools.c			\

src/knot/conf/confio.h

+/*  Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/*!
+ * \file
+ *
+ * Configuration interface.
+ *
+ * \addtogroup config
+ *
+ * @{
+ */
+
+#pragma once
+
+#include "knot/conf/conf.h"
+
+/*! Configuration interface output. */
+typedef struct conf_io conf_io_t;
+struct conf_io {
+	/*! Section. */
+	const yp_item_t *key0;
+	/*! Section item. */
+	const yp_item_t *key1;
+	/*! Section identifier. */
+	const uint8_t *id;
+	/*! Section identifier length. */
+	size_t id_len;
+	/*! Consider item identifier as item data. */
+	bool id_as_data;
+
+	enum {
+		/*! Default item state. */
+		NONE,
+		/*! New item indicator. */
+		NEW,
+		/*! Old item indicator. */
+		OLD
+	} type;
+
+	struct {
+		/*! Section item data (NULL if not used). */
+		conf_val_t *val;
+		/*! Index of data value to format (counted from 1, 0 means all). */
+		size_t index;
+		/*! Binary data value (NULL if not used). */
+		const uint8_t *bin;
+		/*! Length of the binary data value. */
+		size_t bin_len;
+	} data;
+
+	struct {
+		/*! Edit operation return code. */
+		int code;
+		/*! Edit operation return error message. */
+		const char *str;
+	} error;
+
+	/*! Optional processing callback. */
+	int (*fcn)(conf_io_t *);
+	/*! Miscellaneous data useful for the callback. */
+	void *misc;
+};
+
+/*!
+ * Starts new writing transaction.
+ *
+ * \param[in] child Nested transaction indicator.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_begin(
+	bool child
+);
+
+/*!
+ * Commits the current writing transaction.
+ *
+ * \param[in] child Nested transaction indicator.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_commit(
+	bool child
+);
+
+/*!
+ * Aborts the current writing transaction.
+ *
+ * \param[in] child Nested transaction indicator.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_abort(
+	bool child
+);
+
+/*!
+ * Gets the configuration group item subsection list.
+ *
+ * \param[in] key0 Section name (NULL to get section list).
+ * \param[out] io Operation output.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_desc(
+	const char *key0,
+	conf_io_t *io
+);
+
+/*!
+ * Gets the configuration difference between the current configuration and
+ * the active transaction.
+ *
+ * \param[in] key0 Section name (NULL to diff all sections).
+ * \param[in] key1 Item name (NULL to diff all section items).
+ * \param[in] id Section identifier name (NULL to consider all section identifiers).
+ * \param[out] io Operation output.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_diff(
+	const char *key0,
+	const char *key1,
+	const char *id,
+	conf_io_t *io
+);
+
+/*!
+ * Gets the configuration item(s) value(s).
+ *
+ * \param[in] key0 Section name (NULL to get all sections).
+ * \param[in] key1 Item name (NULL to get all section items).
+ * \param[in] id Section identifier name (NULL to consider all section identifiers).
+ * \param[in] get_current The current configuration or the active transaction switch.
+ * \param[out] io Operation output.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_get(
+	const char *key0,
+	const char *key1,
+	const char *id,
+	bool get_current,
+	conf_io_t *io
+);
+
+/*!
+ * Sets the configuration item(s) value.
+ *
+ * \param[in] key0 Section name.
+ * \param[in] key1 Item name (NULL to add identifier only).
+ * \param[in] id Section identifier name (NULL to consider all section identifiers).
+ * \param[in] data Item data to set/add.
+ * \param[out] io Operation output (callback error output).
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_set(
+	const char *key0,
+	const char *key1,
+	const char *id,
+	const char *data,
+	conf_io_t *io
+);
+
+/*!
+ * Unsets the configuration item(s) value(s).
+ *
+ * \param[in] key0 Section name (NULL to unset all sections).
+ * \param[in] key1 Item name (NULL to unset the whole section).
+ * \param[in] id Section identifier name (NULL to consider all section identifiers).
+ * \param[in] data Item data (NULL to unset all data).
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_unset(
+	const char *key0,
+	const char *key1,
+	const char *id,
+	const char *data
+);
+
+/*!
+ * Checks the configuration database semantics in the current writing transaction.
+ *
+ * \param[out] io Operation output.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int conf_io_check(
+	conf_io_t *io
+);
+
+/*!
+ * Returns textual item key part of the operation result.
+ *
+ * \note The result must be deallocated.
+ *
+ * \param[out] io Operation output.
+ *
+ * \return String or NULL.
+ */
+char *conf_io_txt_key(
+	conf_io_t *io
+);
+
+/*!
+ * Returns textual item data part of the operation result.
+ *
+ * \note The result must be deallocated.
+ *
+ * \param[out] io Operation output.
+ *
+ * \return String or NULL.
+ */
+char *conf_io_txt_data(
+	conf_io_t *io
+);
+
+/*! @} */

src/knot/server/server.c

@@ -482,7 +482,14 @@ int server_reload(server_t *server, const char *cf)
 	}
 
 	if (cf != NULL) {
+		// Check for no edit mode.
+		if (conf()->io.txn != NULL) {
+			log_warning("reload aborted due to active config DB transaction");
+			return KNOT_CONF_ETXN;
+		}
+
 		log_info("reloading configuration file '%s'", cf);
+
 		conf_t *new_conf = NULL;
 		int ret = conf_clone(&new_conf);
 		if (ret != KNOT_EOK) {

src/libknot/errcode.c

@@ -133,9 +133,12 @@ static const struct error errors[] = {
 	{ KNOT_YP_ENOID,         "missing identifier" },
 
 	/* Configuration errors. */
-	{ KNOT_CONF_EMPTY,     "empty configuration database" },
-	{ KNOT_CONF_EVERSION,  "invalid configuration database version" },
-	{ KNOT_CONF_EREDEFINE, "duplicate identifier" },
+	{ KNOT_CONF_EMPTY,        "empty configuration database" },
+	{ KNOT_CONF_EVERSION,     "invalid configuration database version" },
+	{ KNOT_CONF_EREDEFINE,    "duplicate identifier" },
+	{ KNOT_CONF_ETXN,         "failed to open another config DB transaction" },
+	{ KNOT_CONF_ENOTXN,       "no active config DB transaction" },
+	{ KNOT_CONF_EMANYTXN,     "too many nested config DB transactions" },
 
 	/* Processing errors. */
 	{ KNOT_LAYER_ERROR, "processing layer error" },

src/libknot/internal/errcode.h

@@ -140,6 +140,9 @@ enum knot_error {
 	KNOT_CONF_EMPTY,
 	KNOT_CONF_EVERSION,
 	KNOT_CONF_EREDEFINE,
+	KNOT_CONF_ETXN,
+	KNOT_CONF_ENOTXN,
+	KNOT_CONF_EMANYTXN,
 
 	/* Processing error. */
 	KNOT_LAYER_ERROR,